US 2011/0308469, US 2012/103266, WO 2009/093965, and US 2010/031889 disclose fully or semi automated rotary milking systems wherein automatic teat cup attachment can be performed by the use of a robot. Each of the milking stalls is provided with teat cups with separate milk tubes up to the vacuum/milk separation (i.e. no cluster is present). The teat cups of each milking stall are retracted to default storage positions subsequent to the milking of an animal therein. The robot fetches teat cups, one at a time, from a magazine of each milking stall and attaches them to the teats of an animal present in the milking stall. US 2012/298043 discloses a robot arm usable with the above milking systems.
WO 2011/086015 and WO 2012/033448 disclose teat cup magazines for storage of teat cups in default storage positions that are usable in the above milking systems. US 2010/058990 discloses another type of teat cup magazine.
EP 2262356 discloses another kind of rotary milking system wherein each milking stall comprises teat cups attached to a cluster, which in turn is connected to a single milk tube up to the vacuum/milk separation. A teat cup attachment robot serves each milking stall in order, wherein the cluster and the teat cups of the milking stall are fetched from default storage positions and are moved to the udder of an animal present in the milking stall, whereupon the teat cups are attached to the teats of the animal.
In each of these automated or semi-automated rotary milking systems, there will be situations when the teat cups (and optionally the cluster if present) are not positioned correctly (i.e. not in the default storage positions) and then the teat cup attachment arrangement (robot) may not be able to grip the teat cups. This may e.g. be caused by a cord attached to the cluster being broken or entangled with one of the teat cups, so that teat cup is not hanging down as it should. Alternatively, it may be caused by improper operation of the devices which are responsible for returning of the teat cups to the default storage positions, e.g. leading to the teat cups (and optionally the cluster if present) not being retracted correctly, i.e. sufficiently, so that the default storage positions are not reached.
Such problems will probably occur more often in rotary milking systems when a teat cup attachment arrangement (robot) serves a plurality of milking stalls and thus a plurality of default storage positions of the teat cups. Further, the milking stalls, and thus the default storage positions of the teat cups, are moving (rotating), which renders the automatic teat cup attachment procedure even harder.
Yet further, the rotary milking system has properties allowing actions to be performed which cannot be performed in stationary milking systems, such as batch wise milking systems, tied up milking systems, or fixed milking robot system installations.
WO 01/93668 discloses a detection device for a stationary milking system for milking an animal. The milking arrangement includes a milking device having at least one teat cup, which has a longitudinal axis and which is able to have a desired orientation (vertically arranged teat cup) and an undesired orientation (horizontally arranged teat cup lying on the floor after kick-off). The detection device includes at least one sensor, arranged to sense the value of a parameter related to said orientations of the teat cup, and a first communication unit for wireless transmission of said value to a second communication unit, which comprises a processor arranged to process said value in order to establish which of said orientations the teat cup has and which is arranged to perform an action if said teat cup has said undesired orientation. The action may be to pull the teat cup from the floor, to switch off the vacuum to the teat cup, and to activate an alarm.
The purpose of the detection in WO 01/93668 is to determine whether a teat cup has been kicked off or in some other way fallen to the floor. The detection device of WO 01/93668 detects orientations of the teat cups, and cannot distinguish between two vertical positions if the orientation of the teat cups is the same.